The present invention relates to devices for delivering substances and methods of making and using them. More particularly, it relates to medical devices for administering or delivering a product in doses, such as injection apparatus, syringes, injection pens, etc., using which a dosed amount of a fluid product, such as insulin, growth hormones or osteoporosis preparations, etc., can be self-administered by a user.
The functional elements of an electronic or mechanical real-time display and of an electronic life timer or device service life timer, as described below, may be used together with an injection pen as described in a U.S. patent application entitled “Injection or Infusion Apparatus Comprising a Service Life Timer” filed on the same day as the present application and owned by the owner of the present application. The elements and functional sub-assemblies of injection apparatus, as described in that patent application, are incorporated into this application by reference, wherein an injection pen in accordance with the present invention may incorporate an embodiment of a dosage display described in the referenced patent application, and/or with regard to sensors, electronics or display elements as described herein.
In injection devices, including pen-type devices, components such as springs or components which are often moved can wear, change or deteriorate due to the strains occurring during use and due to mechanical stresses, and also due to aging processes, such that the correct mode of operation and functional capability of the pen is compromised.
If a user sets a dosage or an amount of a substance to be dispensed by the injection device by displacing the substance from an ampoule inserted in the injection device, then it is advantageous for the user if the dosage currently can be set and/or displayed on a display of the injection device. In known injection apparatus, the dosage set is displayed during and after setting the dosage, and the user can initiate the injection process by pressing a triggering button, wherein the dosage displayed rotates or runs back or is reset from the dosage set to zero after the injection process has been performed.